Field of Invention
The present invention relates to a semiconductor device and a manufacturing method therefor; particularly, it relates to such a semiconductor device which has a stacked cap layer, such that a nitride layer thereof is protected so as not to be damaged by an etchant material, and a manufacturing method therefor.
Description of Related Art
Please refer to FIGS. 1A-1B, which are cross-sectional views illustrating a conventional manufacturing method for a semiconductor device. As shown in FIG. 1A, in the manufacturing method for a conventional semiconductor device 10, a semiconductor stacked structure 19 is formed on a substrate 11. A stacked cap layer 15 is formed on the semiconductor stacked structure 19. The semiconductor stacked structure 19 includes a gate structure 13 and a spacer layer 14. The semiconductor stacked structure 19 is formed on the substrate 11 by the steps of: first, forming a shallow trench isolation (STI) structure 12 in the substrate 11; next, forming the gate structure 13 and the spacer layer 14 on the STI structure 12. As shown by the cross-sectional view of FIG. 1A, the gate structure 13 includes, from bottom to top: a first gate structure 131, a nitride dielectric layer 132, an oxide dielectric layer 133 and a second gate structure 134. The spacer layer 14 includes an oxide spacer layer 14b and a nitride spacer layer 14a. According to the cross-sectional view of FIG. 1A, the stacked cap layer 15 includes, from bottom to top, a first oxide cap layer 151, a nitride layer 152 and a second oxide cap layer 153. A protection layer 16 is formed on the stacked cap layer 15, wherein the protection layer 16 is etched to form an opening 161.
As shown in FIG. 1B, in the following steps for manufacturing the conventional semiconductor device 10, the substrate 11 is etched, and an etchant material (e.g., sulfur hexafluoride (SF6)) is introduced into the opening 161. Undesirably, because sulfur hexafluoride (SF6) would attack the nitride layer 152 of the stacked cap layer 15 (as shown by the arrow in FIG. 1B), the nitride layer 152 will be damaged, to adversely affect the robustness of the conventional semiconductor device 10 is affected.
In view of the above, to overcome the drawbacks in the prior art, the present invention proposes a manufacturing method for a semiconductor device having a stacked cap layer, wherein the nitride layer of the stacked cap layer is protected and not to be damaged by the etchant material.